Inflammatory Markers in the Diagnosis of Fibromyalgia, 2021, Khamisy-Farah et al

Abstract

Background: Fibromyalgia syndrome (FMS) is a chronic disorder characterized by widespread musculoskeletal pain accompanied by various additional symptoms. The prevalence of FMS ranges between 2-8% of the population. The exact pathophysiology of the disease remains unknown, and under certain circumstances it is difficult for the physician to diagnose. Previous studies have shown a correlation between inflammatory biomarkers such as C-reactive protein (CRP) and FMS activity, suggesting that an inflammatory component may play a role in this disease pathogenesis.

Objectives: To investigate the role of certain new inflammatory biomarkers in the diagnosis of patients with FMS.

Methods: In this study data were collected from FMS patients who were admitted to Ziv Medical Center during the period 2013 to 2019 in an attempt to find a connection between inflammatory markers detectable by a traditional complete blood count (CBC) tests such as neutrophil-lymphocytes ratio (NLR), platelet-lymphocyte ratio (PLR), mean platelet value (MPV), red cell distribution width (RDW), and C-reactive protein (CRP) and FMS.

Results: We found significantly higher CRP levels, MPV, and PLR and lower lymphocyte count in the FMS group compared to the control group.

Conclusions: FMS has certain inflammatory components that may be useful in disease diagnosis.

PubMed abstract only at time of posting ,https://pubmed.ncbi.nlm.nih.gov/34954920/

 

My understanding is that FM has not been shown to be an inflammatory rheumatic disease and that CRP levels are not abnormal.
Also, these blood ratio tests are used in assessing infection, cancer, as well as inflammation. They are much less specific than tests for rheumatic inflammation.

That said, there is overlap in that some lupus patients, for example among others, have FM.



From a research article https://www.annlabmed.org/journal/view.html?doi=10.3343/alm.2019.39.4.345

"Nonetheless, accumulating evidence suggests that PLR can provide valuable information to clinicians who encounter multisystem manifestations of rheumatic diseases, which are reflected in shifts in platelet, lymphocyte, neutrophil, or monocyte counts. Interpretation of PLR combined with complementary hematologic indices is advisable to more accurately diagnose inflammatory rheumatic diseases and predict related comorbidities."

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The paper discusses their CRP findings:

Of note, i believe a study for ME has found elevation of CRP compared to controls (I believe it was from the UK biobank) but the CRP results were still within the normal limits.